SELECT
    w.id,
    wp.age,
    w.coins_needed,
    w.power
FROM wands w
    JOIN wands_property wp ON wp.code = w.code
WHERE wp.is_evil = 0 AND w.coins_needed = (
    SELECT
        MIN(coins_needed)
    FROM wands derived_w
    JOIN wands_property derived_wp ON derived_wp.code = derived_w.code
    WHERE derived_wp.age = wp.age AND derived_w.power = w.power
)
ORDER BY w.power DESC, wp.age DESC
;